[Enhancement] Ability to select multiple choices in the Identify pop-up menu

[Bakadori]

Having Aggregate from all providers switched on leaves room to missmatches.

For example, for Arslan Senki, if you choose the Hiromu Arakawa series from the first provider, it will add metadata from the Chisato Nakamura (ranked higher in all results) series. Maybe using Exact name matching would prevent that, but probably also the ability to aggregate from different providers.

Being able to select multiple choices (one per provider) would make sure that it's using the source we want.